History is a wonderful thing. You can learn a lot from it.
The first Wings of Fire book was released in 2012. It was written by Tui T. Sutherland, one of the members in the Erin Hunter group. The book series had progressed until 2021, and by that time Tui had written 15 books, 2 legends, 4 winglets, and 4 graphic novels.
The idea of the Lost Book Series came up after Kaylie and Ginny had a failed attempt at a different podcast (it shall never be mentioned again; Ginny is very ashamed). Ginny, like a normal human bean, was discussing with her family about podcast ideas. And when her mom suggested to do a Wings of Fire podcast, Ginny and the family collectively agreed it was a great idea. Ginny talked about it with Kaylie, and like any sane person, she also agreed it was a perfect podcast idea.